The invention relates to a safety device comprised in an elevator car of an elevator. According to prior art, a protective structure is connected to the bottom part of an elevator car configured to move in an elevator hoistway, which protective structure is either permanently in a vertical position or can be temporarily displaced into a vertical position, when in which vertical position the protective structure forms a vertical protective wall extending downwards from the bottom edge of the door aperture side of the elevator car. The protective wall is called, in English, an apron or a toe guard. A protective wall is needed when stopping the elevator car between floors, because in this case the bottom edge of the elevator car remains above the floor level. An open aperture leading into the hoistway in this case remains between the bottom edge and the floor level, which aperture the aforementioned protective wall is intended to cover. When the protective wall is in a vertical position it covers the aforementioned aperture, so that the transfer of a person or of freight into the hoistway via the aperture is prevented.
It is often appropriate to form the pit of elevator hoistways to be shallow, i.e. the distance between the bottom of the elevator hoistway and the sill of the bottommost floor landing to be short, even shorter than the space needed by the aforementioned protective wall in the vertical position. Owing to this, it is advantageous to connect the aforementioned protective wall to the elevator car in a manner that allows folding, such that the protective wall can be displaced between a vertical operating position and a retracted position folded out of the vertical operating position, when it is in which retracted position the protective wall takes up less space below the car in the vertical direction than when it is in the operating position. A problem with a folding-type protective wall is that the unintended moving of it out of the operating position must somehow be prevented. More particularly the folding of a protective wall out of the operating position under the weight of a person leaning on the protective wall could cause a dangerous situation. For this reason it has been possible to lock the protective wall into the operating position by the aid of separate locking mechanisms. The locking means have, however, been complicated and forming them to be durable and reliable in a space-efficient manner has been awkward.